Drupal 8.x

After updating to Drupal 8.7.7 I am experiencing an issue with my site when trying to add Commerce Products with Variations to the cart. This is related to purchasing Membership which might be tied to the OSA distro that the site is using. I have inherited the site so don't have a ton of detail regarding the integration and if its custom or not. When trying to add the products to cart, I get the following error:

Greetings , I appologize if someone has already asked this question ... I searched the forums and can't seem to get an answer.

I have the latest version of Alfresco Community edition installed with 30K of searchable pdf files (old scanned newspapers)

After logging in and clicking into Content, there is a listing of all your added content with the following columns:

Title, Content Type, Author, Stats, Updated, Operations

There are times I want to see the original publication date of all my content without having to go into the edit page of each piece. How would I add the Published Date to the columns on the Content listing page?

Thanks!

I'm struggling to override the template on the admin interface for a content type. I'm going to need to do several modifications to the edit form to meet the editor's requirements, however, I seem to be unable to get this to override.

The page source gives me the following

Hi All,

I have just deleted a content type that wasn't being used on the site but having done so I have immediately run into "The website encountered an unexpected error. Please try again later." problem. 

A look in the logs shows the following error:

Uncaught PHP Exception Drupal\\Component\\Plugin\\Exception\\PluginNotFoundException: "The "field_item:entity_reference" plugin does not exist.

http://gruplaela.uji.es/__D8/node/39

On this page I have a field called "Authored by" and the field type is Entity Reference. I'm trying to style it but I cant get it to sit inline like the other fields (which are field type Text). Rather the two field items sit on top of each other and push the following field to the right (as if it were float: left in CSS).

What I would like to have is something like this:

Authored by: Patricia Salazar Victòria Codina